The present invention relates to speaker apparatus and television sets, and more specifically to a speaker apparatus provided with a horn having an output port smaller in area than a vibrating surface of a speaker, and a television set equipped with the speaker apparatus.
In general, it is the best that a speaker apparatus directly outputs sound from a speaker without utilizing a horn. A horn, however, is commonly used in a speaker apparatus because of the limited size of a cabinet such as a television set and personal computer where the speaker apparatus is installed.
For example, in the case where a speaker apparatus is integrated in a television set and then speakers are placed on both sides of a cathode ray tube (CRT) thereof , the width of the television set is uselessly enlarged. Therefore, in a conventional television set, a speaker apparatus provided with a horn having a slim and long output port is widely used to minimize the width of the television set.
Such speaker apparatus provided with horns having slim and long output ports include, for example, xe2x80x9cSpeaker system for television setxe2x80x9d disclosed in Japanese Utility Model Publication No. 5-20475, and xe2x80x9cSpeaker system for television setxe2x80x9d disclosed in Japanese Patent Laying-Open No. 7-177443.
In FIG. 7, shown is a perspective view of xe2x80x9cSpeaker system for television setxe2x80x9d disclosed in Japanese Patent Laying-Open No. 7-177443.
In the above-described conventional speaker apparatus, an output port of a horn is required to be larger in area than a vibrating surface of a speaker in order to secure a sufficient sound pressure level. The configuration of the conventional speaker apparatus allows a television set to be narrower in width. However, the height of the television set must be increased due to the decreased width in order to ensure the area of the output port to be larger than the area of the vibrating surface of the speaker. Consequently, the television set has a complicated structure, and a molding die for the speaker apparatus is elaborate and expensive, which makes it difficult to produce the speaker apparatus with a multiple cavity die. Besides, the speaker apparatus occupies a large portion in the television set as a result. This leads to a problem that the structure of the television set can not be freely designed.
Therefore, an object of the present invention is to provide a speaker apparatus in which a sound output port of a horn is smaller in area than a vibrating surface of a speaker while reproducing sound whose quality is equal or similar to that in the conventional art, and a television set equipped with the speaker apparatus.
The present invention has the following features to attain the above-described object.
A second aspect is directed to a speaker apparatus comprising a speaker with a horn,
the horn has a shape in which:
a sound input port is attached to a vibrating surface of the speaker, and a sound output port is smaller in area than the sound input port;
the length from the sound input port to the sound output port is not more than 370 mm;
when representing the area of the opening of the sound input port as A, the area of the opening of the sound output port as B, the length of the horn as L, a distance from the sound input port as X, and an arbitrary integer of not less than 1 as C,
the area Y of the vertical section, of the horn, being parallel to a plane of the sound input port at the distance X can be expressed by the following equation;
Y=(Axe2x88x92B)*(Lxe2x88x92X)c/Lc+B; and
xe2x80x83the sound output port is formed in a position where a center axis of the sound radiated from the speaker does not impinge against an inner wall of the horn.
As described in the above, according to the second aspect, it is possible to make an opening of the sound output port smaller in area than an opening of sound input port in the horn, and at the same time, suppress resonance of sound outputted from the speaker within the horn down to its second resonance frequency and obtain better sound pressure properties as compared with the conventional speaker apparatus. As a result, preferable sound with less dip can be reproduced.
As stated above, the second aspect indicates a preferable length of the horn in the first aspect. Thus, the resonance of sound outputted from the speaker can be suppressed within the horn down to its second resonance.
According to a third aspect, in the second aspect, wherein in the predetermined rule,
when representing an area of an opening of the sound input port as A, an area of an opening of the sound output port as B, a length of the horn as L, a distance from the sound intput port as X, and an arbitrary integer of not less than 1 as C,
an area Y of the vertical section of the horn at the distance X can be expressed by a following equation;
Y=(Axe2x88x92B)xc3x97(Lxe2x88x92X)c/Lc+B.
As mentioned in the foregoing, the third aspect presents a typical equation for calculating each area of the vertical sections of the horn in the second aspect.
According to a fourth aspect, in the second aspect, the shapes of the sound input port and the output port and the vertical section of the horn are any one of circular, oval, or polygonal form, or a combination of the above-described forms.
As described above, according to the second aspect, in the second aspect, it is possible to reduce unwanted sound produced by the resonance within the horn and the strength of installation structure of the horn.
According to a fifth aspect, in the fourth aspect, the opening of the sound input port of the horn is equal to or smaller in area than the vibrating surface of the speaker.
As described above, according to the fifth aspect, in the fourth aspect, it is possible to prevent sound from resonating within the horn.
According to a sixth aspect, in the fifth aspect,
another horn is further provided to the output port of the horn while keeping the entire length no more than 370 mm, wherein
the vertical sectional area of the another horn is constant or a sound output port thereof being broader than a sound input port thereof.
As described above, according to the sixth aspect, in the fifth aspect, the horn can be designed more flexibly.
A seventh aspect is directed to a television set equipped with the speaker apparatus according to any one of the following (a), (b) or (c):
(a) A speaker apparatus, wherein the horn has a shape in which:
a sound input port is attached to a vibrating surface of the speaker, and a sound output port portion for outputting sound inputted to the sound input port is smaller in area than the sound input port;
the length from the sound input port to the sound output port is not more than 370 mm;
when representing the area of the opening of the sound input port as A, the area of the opening of the sound output port as B, the length of the horn as L, a distance from the sound input port as X, and an arbitrary integer of not less than 1 as C,
the area Y of the vertical section, of the horn, being parallel to the plane of the sound input port at the distance X can be expressed by a following equation;
Y=(Axe2x88x92B)xc3x97(Lxe2x88x92X)c/Lc+B; and
xe2x80x83the sound output port is formed in a position where a center axis of the sound radiated from the speaker does not impinge against an inner wall of the horn.
(b) The speaker apparatus as described above in (a), wherein
the shapes of the sound input port and the sound output port and the vertical section of the horn are any one of circular, oval, or polygonal from, or a combination of the above-described forms.
(c) The speaker apparatus as described above in (b), wherein
the opening of the sound input port of the horn is equal to or smaller in area than the vibrating surface of the speaker;
wherein another horn is further provided to the output port of the horn while keeping the entire length no more than 370 mm; and
wherein the vertical sectional area of the another horn is constant or a sound output port thereof being broader than a sound input port thereof.
As described above, the seventh aspect is directed to the television set equipped with the speaker apparatus described in any one of the second, fourth and sixth aspects. The television set can dispose a sound output port in empty space in the front of a cabinet thereof, and reduce the width thereof by being equipped with the speaker apparatus described in any one of the second, fourth and sixth aspects. Besides, since the structure of the speaker apparatus can be simplified, a molding die for the speaker apparatus can be also simplified. This enables production of speaker apparatus with a single multiple cavity die. Consequently, it is possible to provide greater flexibility with the design of the television set.
According to a tenth aspect, in the ninth aspect, wherein
shapes of the sound input port and the sound output port and the vertical section of the horn are any one of circular, oval, or polygonal, or combination thereof.
According to an eleventh aspect, in the tenth aspect, wherein
the opening of the sound input port of the horn is equal to or smaller in area than the vibrating surface of the speaker.
According to a twelfth aspect, in the eleventh aspect, wherein
another horn whose vertical sectional area is constant, or broader toward a sound output port thereof is further added to the output port of the horn.
As described above, the seventh to twelfth aspects are directed to the television set equipped with the speaker apparatus according to the first to sixth aspects. The television set can dispose a sound output port in empty space in the front of a cabinet thereof, and reduce the width thereof by being equipped with the speaker apparatus according to the first to sixth aspects. Besides, since the structure of the speaker apparatus can be simplified, a molding die for the speaker apparatus can be also simplified. This enables production of speaker apparatus with a single multiple cavity die. Consequently, it is possible to provide greater flexibility with the design of the television set.